Grasping device for doffing full bobbins and reloading empty tubes in a spinning frame

ABSTRACT

A grasping device for doffing full bobbins and reloading empty tubes in a spinning frame is disclosed, wherein two grippers provided with expansible chambers are united together and independently actuated. According to the invention, a first gripper comprises a stiff outer sleeve, an inner resiliently yielding sleeve having the ends curled over and fastened to the outside of said stiff sleeve and a couple of comparatively stiff collars snappingly engaged onto said curled ends of the resiliently yielding sleeve so as to lock them in a sealtight manner against the outer wall of said stiff sleeve. The second gripper comprises a first stiff sleeve integral with the stiff sleeve of the first gripper and equipped with a first hole for communication between a first feeding duct for a pressurized fluid and the inner cavity of said first sleeve, with a second hole for communication between a second pressurized fluid feeding duct and a widened annular portion formed in the inner cavity of said first sleeve, and with a third hole which passes also through the stiff sleeve of the first gripper, for establishing a communication between said annular widened portion and the expansible chamber defined between the two sleeves of the first gripper, the second gripper comprises also a second stiff sleeve inserted into said widened annular portion of the inner cavity of the first gripper and equipped with an annular groove for affording a communication between said second and said third hole of the first sleeve, a resiliently yielding sleeve inserted in the interior of said first and said second sleeve and equipped with ends which are curled over and fastened to the outside of said first and said second sleeve and a couple of comparatively stiff collars snappingly engaged onto said curled over ends so as to lock them in a sealtight manner against the outer wall of said stiff sleeves.

United States Patent [191 Viglione [451 May 7,1974

[ GRASPING DEVICE FOR DOFFING FULL BOBBINS AND RELOADING EMPTY TUBES IN A SPINNING FRAME [75] Inventor:

[73] Assignee: Nuova San Giorgio S.p.A., Genova,

Italy [22] Filed: Mar. 8, 1973 217] HP JNNQLL2JQ1 r [30] Foreign Application Priority Data Giovanni Viglione, Genova, Italy 2/1973 Rothke 57/52 Primary Examiner-John Petrakes Attorney, Agent, or FirmEric H. Waters [57] 7 ABSTRACT A grasping device for doffing full bobbins and reloading empty tubes in a spinning frame is disclosed, wherein two grippers provided with expansible cham- AEording to the invention, a first gripper comprises a stiff outer sleeve, an inner resiliently yielding sleeve having the ends curled over and fastened to the outside of said stiff sleeve and a couple of comparatively stiff collars snappingly engaged onto said curled ends of the resiliently yielding sleeve so as to lock themin a sealtight manner against the outer wall of said stiff sleeve. The second gripper comprises a first stiff sleeve integral with the stiff sleeve of the first gripper and equipped with a first hole for communication between a first feeding duct for a pressurized fluid and the inner cavity of said first sleeve, with a second hole for communication between a second pressurized fluid feeding duct and a widened annular portion formed in the inner cavity of said first sleeve, and with a third hole which passes also through the stiff sleeve of the first gripper, for establishing a communication between said annular widened portion and the expansible chamber defined between the two sleeves of the first gripper, the second gripper comprises also a second stiff sleeve inserted into said widened annular portion of the inner cavity of the first gripper and equipped with an annular groove for affording a communication between said second and said third hole of the first sleeve, 3. resiliently yielding sleeve inserted in the interior of said first and said second sleeve and equipped with ends which are curled over and fastened to the outside of said first and said second sleeve and a couple of comparatively stiff collars snappingly engaged onto said curled over ends so as to lock them in a sealtight manner against the outer wall of said stiff sleeves.

1 Claim, 1 Drawing Figure GRASPING DEVICE FOR DOFFING FULL BOBBINS AND RELOADING EMPTY TUBES IN A SPINNING FRAME This invention relates to a catching device for doffing full bobbins and reloading empty tubes in a spinning frame.

A few doffing and reloading device are known for spinning frames, which are based on the use of grippers formed by a stiff outer sleeve and a resiliently yielding inner sleeve, between which a sealtight annular closed chamber in which a pressurized fluid (usually air) can be introduced, adapted to cause a deformation of the resilient sleeve towards a gripping condition of the bobbin or the tube to be removed.

The grippers intended for doffing full bobbins and those intended to reload the empty tubes are generally separated from one another and generally equipped with discrete actuating mechanisms. Recently, the same applicant of the present invention has envisaged, however, an improved device in which a gripper intended for doffing full bobbins and one intended for reloading empty tubes are united together and have very reduced axial dimensions imparted thereto so as to limit the overall bulk of the device.

In such an improved device each of the two ganged grippers is composed by a stiff outer sleeve which is integral to the outer stiff sleeve of the other gripper, by an inner resiliently yielding sleeve equipped with ends which are curled outside the stiff sleeve and adhered thereto in order to ensure a tight seal for the expansible chamber as defined between the two sleeves, and finally by two stiff collars slipped onto the outwardly curled ends of the resilient sleeve. The gripper intended for grasping the full bobbins, which has the larger diameter and thus, under conditions of equal pressure of the fluid, is subjected to a greater stress, is equipped, in addition, with straps which connect the two collars together so as to prevent their being slipped out as the fluid pressure is being applied. Lastly, while the expansible chamber of the gripper having the larger diameter is directly connected to the respective fluid feeding duct, the expansible chamber of the gripper having the lesser diameter is connected to its respective fluid feeding duct through a small tube which is caused to run outside the stiff sleeve of the gripper having the larger diameter.

This kind of arrangement, along with a number of positive properties such as a reduced bulk, the greater simplicity of operation and of the actuating mechanisms involved thereby, exhibits a few shortcomings which render the construction cumbersome and expensive. These drawbacks are mainly inherent in the difficulty of cementing the resilient sleeves (usually of rubber) on the stiff collars (usually of a plastics material), in the necessity of providing the connecting straps for the end collars of the grippers having the larger diameter, and the consequential requirement of fitting such end collars with tongues for hooking up the straps, and, lastly, in the difficulties encountered when building, fastening and sealing the connection tube between the expansible chamber of the gripper having the smaller diameter and the relative feeding duct for the pressurized fluid.

An object of the present invention is thus to provide a device having two ganged grippers of the last mentioned type, which is immune from the above enumerated drawbacks and, more particularly, is simpler and cheaper.

This object is achieved by the device according to this invention, which is characterized in that a first grip per comprises a stiff outer sleeve, a resiliently yielding inner sleeve having its ends curled over and fastened to the outside of the rigid sleeve and a couple of collars which are comparatively stiff and are snappingly slipped onto said curled ends of the resiliently yielding sleeve so as to lock them in a sealtight manner against the outer wall of the stiff sleeve, and that the second gripper comprises a first stiff sleeve integral with the stiff sleeve of the first gripper and provided with a first communication hole between a first pressurized fluid feeding duct and the inner cavity of said first sleeve, a second communication hole being provided between a second pressurized fluid-feeding duct and a widened annular portion of the inner cavity of said first sleeve, and a third hole which passes also through the stiff sleeve of the first gripper, for affording a communication between said widened annular portion and the expansible chamber defined between the two sleeves of the first gripper, a second stiff sleeve inserted insaid widened annular portion of the inner cavity of the first sleeve and equipped with an annular. groove for establishing a communication between said second and third hole of the first sleeve, a resiliently yielding sleeve inserted in the interior of the first and the second sleeve and equipped with ends which are curled over and fastened to the outside of said first and said second sleeve and a couple of comparatively stiff collars snappingly slipped over said curled ends so as to lock them in a sealtight manner against the outer wall of said stiff sleeves. I

It is apparent that the arrangement described above does away with cementing the stiff and the resilient sleeves of the two grippers, and eliminates the connection straps between the end collars of the gripper having the greater diameter, the hooking up tongues for the straps and the connection tube between the expansible chamber of the gripper having the lesser diameter and the relevant feeding duct for the fluid, that is, it does away with all the defects which were responsible for rendering the cost of the twin pincer devices known hitherto exceedingly high. As a matter of fact the fastening obtained between the resilient sleeves and the stiff sleeves (appropriately fitted with external. ribs) of the two grippers permits to dispense with cementing, as well as the snap fitting of the end collars (by exploiting both the yieldability of the curled ends of the resilient sleeves and the even slightest yieldability of the collars) permits to dispense with the connection straps and the relevant hooking tongues while simultaneously ensuring a fully satisfactory tight seal of the expansible chambers of the two grippers. In addition, the replacement of the connection tube between the expansible chamber of the gripper having the lesser diameter and the respective fluid feeding duct by a mere groove which can be obtained by moulding on the outside wall of the second stiff sleeve of the second gripper enables a considerable simplification of the manufacturing steps to be achieved. Summing up, a device having a considerably reduced cost is obtained.

In order to obtain a clearer idea, an exemplary embodiment of the device according to the invention will now be described in detail, referencebeing had to the accompanying drawing which shows the device in axial cross-sectional view.

The device as shown in the drawing essentially comprises two grippers l and 2, the former intended to grasp the full bobbins to be doffed and the latter intended to grasp the empty tubes to be reloaded, the two grippers being united together so as to make up a single assembly which can be assembled by a clamp 3 with a couple of ducts 4 and 5 for feeding compressed air (or another pressurized fluid) which are appropriately controlled in any conventional manner.

The gripper 2 comprises a stiff outer sleeve 6 (for example of a plastics material) equipped at its ends with outer ribs 7, an inner resiliently yielding sleeve 8 (for example of rubber) having the ends curled over and fastened to the exterior of the stiff sleeve (as can be seen in the drawing, the curled ends of the sleeve 8 are so shaped as to be complementary with respect to the end of the sleeve 6) and a couple of comparatively stiff metal collars 9, which, exploiting the resiliency and the shape of the curled ends of the sleeve 8 and the comparative yieldability and the shape of the collars 9, are snappingly engaged onto the curled ends of the sleeve 8 so as to lock them in a sealtight manner against the ends of the sleeve 6. On the bottom collar 9, lastly, there is snappingly engaged a nozzle 10 having the function of facilitating the introduction of empty tubes to be grasped.

The gripper 1, in turn, comprises a first stiff sleeve 11 (for example of a plastics material) integral with the stiff sleeve 6 of the gripper 2 and equipped, inaddition to a similarly shaped outer end, with a first hole 12 for affording a communication between the duct 5 and the inner cavity of the same sleeve 11, with a second hole 13 for establishing a communication between the duct 4 and an annular widened portion of the same sleeve, and with a third hole 15 which, passing also through the sleeve 6 of the gripper 2, establishes a communication between the widened annular portion 14 aforesaid with the expansible chamber defined between the sleeves 6 and 8 of the gripper 2. The annular widened portion 14 of the inner cavity of the sleeve 11 is filled with a second stiff sleeve 16 (for example, of a plastics material) which is provided, in addition to an outer end shaped as that of the sleeve 11, with an annular groove 17 adapted to establish a communication between the holes 13 and 15 and with two additional annular grooves for housing annular seal rings 18 and 19. In the inner cavity as defined by the sleeves 11 and 16, a resiliently yielding sleeve 20 is inserted (for example of rubber), whose ends are curled over and fastened to the outside of the shaped ends of the sleeves 11 and 16 in the same way in which the curled ends of the sleeve 8 of the gripper 2 are fastened to the outside of the shaped ends of the sleeve 6 of the same gripper 2. Still in the same way as the gripper 2, on the curled ends of the sleeve 20 there are snappingly engaged two comparatively stiff metal collars 21, having the task of locking the curled ends to ensure the required tight seal for the expansible chamber defined between the sleeves' 11, 16 and 20.

The operation of the device shown in the drawing can be readily understood. if one desires to take a full bobbin, the device should be positioned, at the outset, in such a way that the bobbin is inserted into the gripper 1, whereafter the control means for the duct 5 are actuated so as to provide a compressed air feed (or another pressurized fluid). Through the hole 12 the compressed air then reaches the expansible chamber of the gripper l, where the deformation of the resiliently yielding sleeve or diaphragm 20 is caused to occur towards a condition of gripping for the bobbin. The subsequent doffing of the device obviously brings about the doffing of the bobbin. lf, conversely, it is desired to take an empty tube for placing it instead of a full bobbin which has already been removed, the device is so positioned that the tube is inserted into the gripper 2 whereafter compressed air (or another pressurized fluid) is introduced into the duct 4 and, through the hole 13, the channel 17 and the hole 15, reaches the expansible chamber of the gripper 2, where the deformation of the resiliently yielding sleeve of diaphragm 8 is caused to take place towards a condition of grasping for the tube; the subsequent lifting of the device obviously brings about the removal of the tube.

What is claimed is:

l. A grasping device for doffing full bobbins and reloading empty tubes in a spinning frame, of the kind comprising two grippers having chambers which can be expanded by a pressurized fluid, said grippers being united together and independently actuated, characterized in that a first gripper comprises a stiff outer sleeve, an inner resiliently yielding sleeve having the ends curled over and fastened to the outside of said stiff sleeve and a couple of comparatively'stiff collars snappingly engaged onto said curled ends of the resiliently yielding sleeve so as to lock them in a sealtight manner against the outer wall of said stiff sleeve, and in that the second gripper comprises a first stifi' sleeve integral with the stiff sleeve of the first gripper and equipped with a first hole for communication between a first feeding duct for a pressurized fluid and the inner cavity of said first sleeve, with a second hole for communication between a second pressurized fluid feeding duct and a widened annular portion formed in the inner cavity of said first sleeve, and with a third hole which passes also through the stifi sleeve of the first gripper, for establishing a communication between said annular widened portion and the expansible chamber defined between the two sleeves ofthe first gripper, a second stiff sleeve inserted into said widened annular portion of the inner cavity of the first gripper and equipped with an annular groove for affording a communication between said second and said third hole'of the first sleeve, a resiliently yielding sleeve inserted in the interior of said first and said second .sleeve and equipped with ends which are'curled over and fastened to the outside of said first and said second sleeve and a couple of comparatively stiff collars snappingly engaged onto said curled over ends so as to lock them in a sealtight manner against the outer wall of side stiff sleeves. i I l 

1. A grasping device for doffing full bobbins and reloading empty tubes in a spinning frame, of the kind comprising two grippers having chambers which can be expanded by a pressurized fluid, said grippers being united together and independently actuated, characterized in that a first gripper comprises a stiff outer sleeve, an inner resiliently yielding sleeve having the ends curled over and fastened to the outside of said stiff sleeve and a couple of comparatively stiff collars snappingly engaged onto said curled ends of the resiliently yielding sleeve so as to lock them in a sealtight manner against the outer wall of said stiff sleeve, and in that the second gripper comprises a first stiff sleeve integral with the stiff sleeve of the first gripper and equipped with a first hole for communication between a first feeding duct for a pressurized fluid and the inner cavity of said first sleeve, with a second hole for communication between a second pressurized fluid feeding duct and a widened annular portion formed in the inner cavity of said first sleeve, and with a third hole which passes also through the stiff sleeve of the first gripper, for establishing a communication between said annular widened portion and the expansible chamber defined between the two sleeves of the first gripper, a second stiff sleeve inserted into said widened annular portion of the inner cavity of the first gripper and equipped with an annular groove for affording a communication between said second and said third hole of the first sleeve, a resiliently yielding sleeve inserted in the interior of said first and said second sleeve and equipped with ends which are curled over and fastened to the outside of said first and said second sleeve and a couple of comparatively stiff collars snappingly engaged onto said curled over ends so as to lock them in a sealtight manner against the outer wall of side stiff sleeves. 